This invention relates to pillows which provide support for a person's head, neck and shoulders in a reclining or supine position, and more particularly concerns such pillows capable of providing yieldable support of controllable softness and thickness, but which can be placed in a storage mode occupying little space.
The use of a liquid-filled support member to uniformly support the weight of the human body is known and is used extensively in the construction of waterbed mattresses. The fact that water is a dense material has, however, limited its use as a support medium. A waterbed mattress is supported by a heavy frame and the mattress is not moved after it is inserted in the frame and filled with water. Thus, the weight of water within a waterbed mattress does not detract significantly from the use of water as a support medium since a waterbed mattress remains relatively fixed in position.
Water has not been used, however, as a support medium for objects which are moved from place to place during usage, such as pillows. Pillows, and like objects, must be relatively light in weight in order to be mobile. The use of a relatively dense support liquid, such as water, within a pillow would tend to make the pillow immobile and, therefore, unusable.
In view of the recognized usefullness of a liquid, such as water, in providing uniform support, it would be desirable to provide a construction that is able to use water as a support medium and yet is reasonably light in weight. Such a construction could then be used, for example, to provide pillows or similar objects for supporting the human body which would be relatively light and mobile.
Additionally, it would be desirable if a support construction could be provided which used water as a support medium, is relatively light in weight, and yet is relatively simple in structure. Such a construction could then be mass-produced and sold at a relatively low price.
U.S. Pat. No. 4,247,963 to Reddi discloses a pillow having a central air compartment and outer compartments that confine a layer of water. Such design affords good comfort to the user because the primary cushioning means is the layer of water which, by virtue of its displacement characteristic, conforms to the contour of the user's head, neck and shoulders. However, in the Reddi pillow, movement of the water during its displacement is primarily in a horizontal direction. Such direction of motion produces a sensation which is often disconcerting to the user.
One object of the present invention is to provide a pillow of generally rectangular shape capable of being expanded in thickness for use, but collapsible to a substantially flat storage mode when not needed.
Another object of this invention is to provide a pillow of the aforesaid objective wherein changes in thickness do not change its overall dimensions in width and length.
A further object of the present invention is to provide a pillow of the aforesaid nature having separate interior compartments for holding air and water, and the thickness of the pillow is dependent upon the quantities of air and water held by said compartments.
A still further object of the present invention is to provide a pillow of the aforesaid nature wherein said water-holding compartment is disposed exteriorly of said air-holding compartment.
Yet another object of this invention is to provide a pillow of the aforesaid nature of rugged and durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.